The assessment of arc flash incident energy and the mitigation of the associated hazards in naval platform applications is now well defined and understood, with many previous conference papers having been presented, supported by published guidance notes and standards, such as IEEE1584, NFPA 70E, BR2000(52)-1 and Lloyd’s Register Arc Flash guidance document. However, the assessment of the resultant effects of any arc blast on compartment overpressure and the mitigation of the associated hazards to ships structure and ship’s staff are not yet well defined or understood. Literature indicated that considerable damage could be caused to brick built substations and concern was raised about the possible impact on ship structure and personnel safety. With the above in mind, BAE Systems Naval Ships has developed a modelling tool for assessing the effects of an arc blast on a switchboard room compartment and any personnel that may be within the blast boundary. The toolset uses a spatial representation of the switchboard room being assessed, along with the electrical system fault level data, calculated through the normal power system modelling activities, to calculate the pressure rise resulting from an arcing fault. The developed modelling tool allows engineers the ability to perform calculations of arc blast pressure rise for the purpose of identifying the degree of hazard due to pressure and identifying applicable mitigation activities.